1. Field of the Invention
The present invention relates to vehicular lamps and more particularly to a vehicular lamp structure in which a holding protrusion that holds an electronic part is provided on a surface of a wiring board having thereon the electronic part.
2. Description of the Related Art
There are vehicular lamps in which a light source unit having a light source such as a semiconductor light emitting element that emits light is provided in a lamp casing formed by a cover and a lamp housing.
One type of such light source units includes an electronic part such as a light source, a resistive element, etc. in addition to a wiring board on which a circuit pattern is formed and the electronic parts are mounted (see Japanese Patent Application Laid-Open (Kokai) No. 2006-147330, for example).
A vehicular lamp described in Japanese Patent Application Laid-Open (Kokai) No, 2006-147330 provides, among others, an increased freedom of design choice by forming a plurality of mounting surfaces, which face different directions, on a wiring board, and mounting electronic parts on the plurality of mounting surfaces. More specifically, a light source is mounted on one mounting surface of the wiring board, and a resistive element is mounted on the other mounting surface (see FIG. 5 of Japanese Patent Application Laid-Open (Kokai) No. 2006-147330).
In the light source unit described above, the electronic parts are typically bonded to the wiring board by reflow soldering. In the reflow soldering, the electronic parts are placed on solder paste applied to the wiring board, and in this state, the solder paste is melted by heating in a reflow oven and then the solder paste is solidified by cooling, thus allowing the electronic parts to be soldered to the wiring board.
In the vehicular lamp described in Japanese Patent Application Laid-Open (Kokai) No. 2006-147330, however, since the two mounting surfaces facing different directions are formed on the wiring board, at least one of the mounting surfaces is tilted with respect to the horizontal direction when soldering is performed. Accordingly, when the light source or the resistive element is set on the wiring board or when the solder paste is heated in the reflow oven, the light source or the resistive element that is to be mounted on the tilted mounting surface may be displaced with respect to the wiring board or may drop from the wiring board due to the gravity.